Operating element for a domestic appliance

Abstract

A control element (110) for a household appliance (100) comprises a light source (130) and a light sensor (135); and a transparent disc (120) for covering the light source (130) and the light sensor (135). The disc (120) is elastically deformable depending on an actuating force acting upon it; and the disc (120), the light source (130), and the light sensor (135) are arranged relative to one another such that a first part (140) of a luminous flux provided by the light source (130) passes through the disc (120), and a second part (145) of the luminous flux is reflected by the disc (120) in the direction of the light sensor (135). Furthermore, a processing device (165) is provided for determining the actuating force based on a luminous flux detected by the light sensor (135).

Description

[0001] The present invention relates to a control element for a household appliance. In particular, the invention relates to a haptic control element with force detection.

[0002] A household appliance includes a control element to operate a predetermined function of the appliance. For example, the appliance might be a dishwasher, and the control element could be used to select one of several possible wash programs.

[0003] In some cases, it is desirable to control a function based on the actuation force applied to the control element. For this purpose, the control element can have a flexible disc that can be actuated, for example, by a user's finger. Actuation can be achieved, in particular, with an actuation force acting perpendicular to the disc. Deformation of the disc can be detected by an integrated optical sensor located on the side of the disc facing away from the user.

[0004] To better inform the user about which function is available when the dial is pressed, the dial can be marked with a corresponding symbol indicating the function. The area of ​​the symbol can be illuminated by a lighting device to allow operation even in dark environments.

[0005] Such a control element has a complex design. The deformation sensor and the lighting unit can occupy the same installation space, making integration difficult.

[0006] One of the problems underlying the present invention is to provide an improved control element, particularly for a household appliance. The invention solves this problem by means of the subject matter of the independent claims. Dependent claims describe preferred embodiments.

[0007] According to a first aspect of the present invention, a control element for a household appliance comprises a light source and a light sensor, as well as a transparent disc for covering the light source and the light sensor. The disc is elastically deformable depending on an actuating force acting upon it; and the disc, the light source, and the light sensor are arranged relative to one another such that a first part of a luminous flux provided by the light source passes through the disc, and a second part of the luminous flux is reflected by the disc in the direction of the light sensor. Furthermore, a processing device for determining the actuating force based on a luminous flux detected by the light sensor is provided.

[0008] Advantageously, an optical sensor can be used to detect deformation of the disc, and the disc can be illuminated by a single light source. This allows for a more compact design of the control element. The light source can be positioned to ensure homogeneous illumination of the disc. Optionally, multiple light sources are provided, preferably arranged at equal distances from the disc, so that a predetermined section of the disc is uniformly illuminated. The luminous flux incident on the light sensor can originate from one or more of the light sources. The control element can be flexibly used to combine a predetermined actuation characteristic with a predetermined illumination characteristic. The light source and the light sensor can comprise discrete components, allowing for greater flexibility in their application.Preferably, the light sensor and a light source are each implemented as a surface-mount device (SMD) and mounted on a common circuit board. The circuit board can be located on one side of the disc, while a user can operate the other side of the disc.

[0009] The processing unit is preferably configured to control a predetermined function of the household appliance depending on the specific actuating force. In one embodiment, the function can only be controlled if the actuating force exceeds a predetermined threshold. In another embodiment, several thresholds of varying sizes are provided, whereby different functions can be controlled depending on whether the actuating force exceeds a corresponding threshold. A section of the disk can thus be used to control different functions, thereby increasing the number of functions that can be controlled on a predetermined area of ​​the disk. In other words, the density of controllable functions on the household appliance can be increased by using multiple functions.In another embodiment, a function can be parameterized depending on the force applied. For example, a cooktop can be controlled by means of the control element, whereby the provided heat output depends on the magnitude of the actuation force.

[0010] In yet another embodiment, the control element can be used to implement a child safety lock. In this case, the processing unit is configured to determine when the actuation force exceeds a predetermined threshold; and, if so, to activate another control element of the household appliance depending on the actuation.

[0011] The additional control can only be activated once the existing control has been operated with a force that a small child would not be expected to exert. Optionally, activation of the additional control can be set to require that the existing control is operated with a predetermined force for a predetermined period. This can improve the safety of potentially dangerous household appliances such as irons or stoves, preventing them from being used by small children.

[0012] Preferably, the disc includes a mask to imprint a predetermined pattern onto the first luminous flux. The pattern can indicate a function controllable by actuating the control element. In one embodiment, the pattern includes a symbol. The symbol can be monochrome and simply comprise covered and uncovered sections. In another embodiment, the pattern comprises sections of varying transparency. This allows different brightness levels to be controlled in the sections. For example, a gradient of brightness can be displayed on a surface. The pattern can be displayed in the manner of a grayscale image, whereby the first luminous flux need not necessarily be white light, but can be light of any color. In yet another embodiment, the pattern comprises differently colored sections.The sections can be rasterized, and several primary colors can be provided, which can be distributed proportionally within the raster elements. The pattern can thus be displayed in multiple colors. If the raster is chosen to be sufficiently small, a photorealistic representation can be achieved. For example, the control element can be used to set an oven's operating program to bake pizza, and the pattern can represent an image of a pizza.

[0013] The lens can comprise or be composed of multiple layers. Each layer can, in particular, consist of a film, a foil, or a lens. For example, a protective layer, a diffusion layer, a polarizing layer, a dark filter, an adhesive layer, and / or an electrode layer can be stacked on top of each other in a suitable manner. One of the layers can support the mask. An air gap can be provided between the layers of the lens.

[0014] The mechanical and, in particular, elastic properties of the disc can be influenced by one of its constituent layers. For example, the degree of deformation of the disc when actuated with a predetermined force can be controlled based on the thickness and / or material of one of the layers. In one embodiment, a diffusion layer is provided to homogenize the transmitted light flux. In another embodiment, the thickness of this layer is selected to achieve predetermined elastic properties of the disc. In other embodiments, one or more of the other layers can also be varied accordingly.

[0015] In another embodiment, an opaque (non-transparent) section of the mask is designed to reflect the luminous flux emanating from the light source. The mask can thus simultaneously be used to prevent the luminous flux from passing through and to reflect the luminous flux from the light source to the light sensor. In the case of partial transparency of this section of the mask, partial reflection of the luminous flux can also occur.

[0016] Optionally, a reflective element is provided, attached to the disc to reflect a portion of the luminous flux incident from the light source. This reflective element can have a relatively small horizontal extent and be positioned on a section of the disc where the luminous flux from the light source is reflected towards the light sensor, depending on the disc's deformation. By appropriately positioning the light source, and optionally additional light sources, and further optionally by using a suitable diffusion layer, it is largely possible to prevent the reflective element from casting an unwanted dark shadow on an observer of the disc.

[0017] The disc can include an electrode; the processing device is configured to detect contact with the disc based on a change in the electrode's capacitance. This can be a capacitive touch or proximity switch integrated with the force-sensitive control element. For example, the control element can detect operation or contact even if the disc does not deform or if the deformation is too small to be detected by the described optical arrangement. More preferably, the processing device is configured to control a function of the household appliance depending on the contact. The electrode can, for example, comprise an arrangement of fine conductors (mesh), a vapor-deposited conductor layer, or a conductive layer.

[0018] In a further embodiment, a location or point where the disc is touched is determined, for example, capacitively, in particular by means of the electrode, and only one force with which the disc is actuated is determined by means of an optical sensor described herein, i.e., by means of the light source and the light sensor. Advantageously, actuating forces at different points on the disc can be determined using only a single optical sensor. The orientation of an actuated point relative to the sensor can be taken into account when determining the actuating force. In particular, leverage forces between the actuated point and the reflecting point can be considered. The force determination can then be compensated accordingly, so that correct forces can be determined at different points.This allows multiple force-sensitive and backlit control elements on the screen to be scanned using only one optical and one capacitive sensor.

[0019] The control element can include a support element to limit deformation of the disc to the section containing the light source and light sensor. This allows for better control of the disc's elastic properties in the area of ​​the light source and sensor. Furthermore, the disc can have multiple sections that can be actuated independently, with actuation forces for each section being determined separately.

[0020] In a particularly preferred embodiment, the disc comprises several sections, each section being assigned independent means for detecting actuation and / or contact with a section. A section can include a capacitive sensor and / or an optical detection device, as described herein, for determining the actuation force of the disc. Different sections can be scanned differently. This makes it easy to design even a complex user interface for the household appliance. For example, a control element that an operator can move with their finger (slider) can be purely capacitive, while another control element can be additionally or exclusively configured to determine an actuation force.

[0021] The control element can include an actuator connected to the disc. The processing unit is then configured to control the actuator depending on a detected actuation. This allows haptic feedback about the actuation of the control element to be provided. The actuator can, for example, include a pulse generator or a vibration element. In another embodiment, optical feedback about the actuation of the control element can also be provided by temporarily changing the intensity of the luminous flux of the light source.

[0022] According to a further aspect of the present invention, a control unit for a household appliance comprises an operating element as described herein. Preferably, the control unit comprises several operating elements that may use different sections of a common disk. The processing unit can be configured to determine a user input and forward it to a device for controlling the household appliance. In another embodiment, the control unit is configured to control the household appliance depending on a detected user input.

[0023] According to yet another aspect of the present invention, a household appliance comprises a control element or a control device described herein.

[0024] Non-limiting embodiments of the invention are now described in more detail with reference to the accompanying figures, in which: Figure 1: a household appliance; Figure 2: a luminous flux at a light sensor; Figure 3: an exemplary arrangement of layers of a control element disc; and Figure 4: an exemplary user interface of a household appliance. represent.

[0025] Figure 1 Figure 1 shows a household appliance 100 with a control unit 105. The control unit 105 comprises at least one operating element 110, which is designed to be operated by a person 115. Thus, the control unit 105 can form a user interface for the household appliance 100.

[0026] The control element 110 comprises a transparent disc 120 with a top and a bottom. The top side faces the person 115. A circuit board 125 is arranged at a predetermined distance from the bottom side of the disc 120. This circuit board carries at least one light source 130 and a light sensor 135. In the illustrated exemplary embodiment, several light sources 130 are provided, distributed on the circuit board 125 in such a way that they collectively provide a predetermined luminous flux.

[0027] A luminous flux provided by a light source 130 strikes the disc 120 from below. While a first portion 140 of the luminous flux passes through the disc 120, a second portion 145 is reflected from its surface and strikes the light sensor 135. The intensity of the luminous flux detectable by the light sensor 135 depends on the degree to which the disc 120 has been deformed by the action of the person 115. The action is performed with an actuating force that preferably acts substantially perpendicular to a surface of the disc 120. In the illustrated embodiment, the disc 120 is deflected and deformed locally downwards by the actuating force.

[0028] To limit the deformation to a predetermined section of the disk 120, one or more support elements 150 can be provided. A support element 150 can act between the disk 120 and a housing or chassis of the household appliance 100. In the present embodiment, the support is provided, for example, against the circuit board 125.

[0029] A light source 130 can be controlled by means of a driver 155. The light source 130 is preferably designed as a light-emitting diode (LED), with different embodiments available with respect to size, mounting method, luminance, wavelength range, current consumption, etc. A measuring amplifier 160 can be provided for processing a sensor signal from the light sensor 135; this amplifier can be configured, for example, separately, as part of the light sensor 135, or as part of the processing unit 165. Optionally, the measuring amplifier 160 includes an analog-to-digital converter.

[0030] A processing unit 165 is configured to determine an actuating force acting on the disk 120 based on a sensor signal from the light sensor 135. This determination can be based on a known modulus of elasticity of the disk 120, which establishes a relationship between deformation and the magnitude of an actuating force.

[0031] Optionally, the processing device 165 is additionally configured to determine the approach of person 115 to disk 120 capacitively. For this purpose, an electrode 170 can be provided on disk 120, which is connected to the processing device 165. As explained in more detail below, the electrode 170 can comprise one of several layers of disk 120.

[0032] The processing unit 165 is optionally configured to provide feedback to the person 115 regarding the activation of the control element 110. Upon detection of activation, visual feedback can be provided by activating one or more of the light sources 130. In addition, an actuator 175 attached to the disc 120 can be activated to provide haptic feedback. The actuator 175 can, for example, be configured to transmit a pulse or vibration to the disc 120.

[0033] A signal or message regarding the actuation of the disc 120 can be provided via an interface 180. The household appliance 100 can be controlled based on this signal, in particular by executing a predetermined function that is associated with a detected actuation. If the household appliance 100 is controlled directly by the control unit 105, the signal can, in particular, be directed to an actuator of the household appliance 100.

[0034] Figure 2 Figure 200 shows an exemplary relationship between a luminous flux l, detected by a light sensor 135 of a control element 110, and a deformation of the disk 120. The luminous flux I is shown in a vertical direction, and the vertical distance between the disk 120 and the light sensor 135 or the light source 130 is shown in a horizontal direction. This distance is shown in Figure 1 applied and marked with h.

[0035] At a predetermined distance 205, the luminous flux l reaches its maximum. If the distance h is less than the predetermined distance 205, the deformation is determined primarily based on the direction in which the second part 145 of the luminous flux from the light source 130 is reflected. If the distance h is greater than the predetermined distance 205, the absolute influence of the distance h predominates in determining the deformation.

[0036] The representation of Figure 2 It starts from a light source 130, which is designed as a light-emitting diode (LED) and whose luminous intensity decreases in a cone shape depending on the direction of illumination.

[0037] Figure 3 shows a representation of an exemplary disk 120, which is composed of different layers.

[0038] The disc, in an exemplary manner, comprises 120 in the representation of Figure 3From top to bottom, a protective layer 305, a dark filter 310, a color filter 315, a diffusion layer 320, an electrode layer 325, an adhesive layer 330, a dimming layer 335, and a light-guiding layer 340. It should be noted that in other embodiments of a disc 120, other layers 305 to 340 may be provided, and that the order of the layers 305 to 340 may be varied. Furthermore, an air gap or space may be provided between individual layers 305 to 340.

[0039] The protective layer 305 is designed to be touched by a person 115. The protective layer 305 can be made of, for example, acrylic or glass. The dark filter 310 can block the passage of light in predetermined sections. In particular, the dark filter 310 can allow the passage of light only in the area of ​​a control element 110 and not between two adjacent control elements 110. The color filter 315 can implement a single- or multi-colored mask that imprints a predetermined pattern onto a transmitted light stream. For a viewer, the pattern can, for example, form a symbol or a representation.

[0040] The diffusion layer 320 is designed to make the transmitted luminous flux as homogeneous as possible. This ensures a uniform luminance across the surface of the disc 120 in the relevant section of the control element 110. The electrode layer 325 can support the electrode 170. For this purpose, the electrode layer 325 can, for example, comprise a transparent but electrically conductive material, be coated with a conductive material such as metal, or include thin conductive structures.

[0041] The adhesive layer 330 is designed to bond two adjacent layers together. The glare-blocking layer 335 can be used to block light entering the pane 120 at an angle. The light-guiding layer 340 can act as a kind of frame that allows light to pass through only in predetermined sections.

[0042] It should also be noted that individual layers 305 to 340 can be applied to the upper or lower surface of a foil or film. Adjacent layers 305 to 340 can thus be integrated together. For example, the color filter 315 can be printed onto the diffusion layer 320.

[0043] Figure 4 Figure 1 shows an exemplary user interface 400 of a household appliance 100. The illustration depicts a view of an exemplary dial 120 of a control unit 105 of a household appliance 100. The illustration is oriented towards the viewer and may appear as such to a person 115 operating the household appliance 100. For the purposes of this illustration, an oven is assumed to be the household appliance 100. Other household appliances, such as a cooktop, a coffee machine, a dishwasher, an iron, a washing machine, or a clothes dryer, may also be included.

[0044] An exemplary first control element 405 is configured to deactivate a child safety lock of the control unit 105. For this purpose, the first control element 405 is configured to determine an actuation force. More precisely, the first control element 405 is preferably configured to determine that an applied actuation force exceeds a predetermined value for a predetermined duration. This value can be chosen to be so high that a small child would not normally be able to exert such an actuation force.

[0045] A second example control element 410 is configured to input an analog value, for example, a desired oven temperature. This second control element 410 is only capacitively scanned and allows the user to determine a location on the disk 120 where a body part of person 115, for example, a fingertip, is located. The analog value can be set by person 115 moving this location to the right or left.

[0046] A third exemplary control element 415 is configured to control the convection operation of the household appliance 100. For this purpose, the third control element 415 can support both capacitive and force-based sensing. If person 115 only briefly touches the third control element 415, a fan of the oven 100 can be switched on or off. If person 115 presses the third control element 415 with a certain actuation force, the speed of the fan can be set depending on the actuation force.

[0047] It should be noted that the examples mentioned are merely intended to illustrate a technique proposed herein for an improved control element. Different household appliances 100 may include different control elements 110, each capable of controlling adapted functions of the household appliance 100. Reference sign

[0048] 100 Household appliance 105 Control unit 110 Operating element 115 Person 120Disc 125Circuit board 130Light source 135Light sensor 140 First part of the luminous flux, through the disc 145 Second part of the luminous flux, reflected at the disc 150 Supporting element 155 Driver 160 Measuring amplifier 165 Processing unit 170 Electrode 175 Actuator 180 Interface 200 Relationship 205 Predetermined distance l Luminous flux h Distance 305 Protective layer 310 Dark filter 315 Color filter 320 Diffusion layer 325 Electrode layer 330 Adhesive layer 335 Dimming layer 340 Light guiding layer 400Operating surface 405First operating element, with force determination 410Second operating element, with capacitive determination 415Third operating element, with capacitive and force determination

Claims

1. Control element (110) for a household appliance (100), wherein the control element (110) comprises the following elements: - a light source (130) and a light sensor (135); - a transparent disc (120) for covering the light source (130) and the light sensor (135); - wherein the disc (120) is elastically deformable depending on an actuating force acting upon it; - wherein the disc (120), the light source (130) and the light sensor (135) are arranged relative to each other such that a first part (140) of a luminous flux provided by the light source (130) passes through the disc (120) and a second part (145) of the luminous flux is reflected at the disc (120) in the direction of the light sensor (135); and - a processing device (165) for determining the actuating force on the basis of a luminous flux detected by the light sensor (135).

2. Control element (110) according to claim 1, wherein the processing device (165) is configured to control a predetermined function of the household appliance (100) depending on the specific actuating force.

3. Control element (110) according to claim 2, wherein the processing device (165) is configured to determine that the actuating force exceeds a predetermined threshold; and to activate a further control element (110) depending on the actuating force.

4. Control element (110) according to one of the preceding claims, wherein the disc (120) comprises a mask to imprint a predetermined pattern on the first luminous flux.

5. Control element (110) according to claim 4, wherein the disc (120) comprises several layers (305-340), and one of the layers (315) carries the mask.

6. Control element (110) according to one of claims 4 or 5, wherein an opaque section of the mask is configured to reflect a luminous flux radiating from the light source (130).

7. Control element (110) according to one of the preceding claims, wherein a reflective element is attached to the disc (120) to reflect a portion (145) of the luminous flux incident from the light source (130).

8. Control element (110) according to one of the preceding claims, wherein the disk (120) comprises an electrode (170); and the processing device (165) is configured to determine a contact of the disk (120) on the basis of a change in the capacitance of the electrode.

9. Control element (110) according to claim 8, wherein a location where the disk (120) is touched is determined by means of the electrode (170) and a force with which the disk (120) is actuated at the location is determined by means of the light source (130) and the light sensor (135).

10. Control element (110) according to one of the preceding claims, further comprising a support element (150) to limit deformation of the disk (120) to a section in which the light source (130) and the light sensor (135) are arranged.

11. Control element (110) according to one of the preceding claims, wherein the disk (120) comprises several sections; and the sections are assigned independent devices for detecting an actuation and / or touching of a section.

12. Control element (110) according to one of the preceding claims, further comprising an actuator (175) connected to the disk (120); wherein the processing device (165) is configured to control the actuator depending on a detected actuation.

13. Control device (105) for a household appliance (100); wherein the control device (105) comprises an operating element (110) according to one of the preceding claims.

14. Household appliance (100) comprising an operating element (110) according to any one of claims 1 to 12 and / or a control device according to claim 13.

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